Valve for power transmissions



L. R. TWYMAN VALVE FOR POWER TRANSMISSIONS Feb, 13, 1951 v Filed sept. 15, 194e IN VEN TOR.

BY L. RAYMOND TWYMAN f n l ATTORNEY lfatented Feb. 13, 1951 vLVE FOR POWER TRNSMISSIONS L. Raymond Twyman, Bloomfield Township,

Oakland County, Mich.

Application September 13, 1946, Serial No. 696,650

4 Claims.

. l This invention relates to power transmissions, particularly to those of the type comprising two or more fluid pressure energy translating devices,

one of which may function as a pump and another as a fluid motor. i

The invention is more particularly concerned with an improved variable throttle valve for use in such a power transmission as well as in other places where a variable orice may be required. `In the patent to Herman No. 2,343,375, there is disclosed a flow regulating valve of the type having a variable throttle and the compensating valve connected thereto, and arranged to be responsive to the pressure drop across the throttle in a manner to maintain that'pressure drop constant and thereby maintainthe flow rate through the throttle constant independently of pressure 2 i f control valve embodying a preferred form of the present invention. l Figure 2 is a sectional view on line 2-2 of Figure 1. Figure 3 is a fragmentary view corresponding to a portion of Figure 1, With the parts in a dif.` ferent position. f Figure 4 is a fragmentary sectional view on line 4--4 of Figure 1.

Figure 5 is a fragmentary sectional view on line 5 5 of Figure 2.

In the preferred embodiment of the invention illustrated, the adjustable throttle has been incorporated nn a flow regulating valve of the type commonly used for maintaining regulated flow.-

.V rates in uid power transmission systems. It will applied to the regulating valve as `a whole. In

' passing through the valve.

Various constructions have been utilized for providing an orifice with thin edges and it is a relatively simple problem where the size of the orifice may be fixed.` However, where the orice size must be varied, as by a manual adjustment, it has heretofore, been necessary to 'provide some sort of shutter action by which a portion of themaximum orifice opening is closed offby one or more sliding or rotating shutter members. Because the two relatively movable walls of the orifice must be in different members and in different planes, such constructions only approximate the desirable results obtained with a true thin edged orifice. l'

It is an object of the present invention, therefore, to provide an improved construction for a thin edged orifice wherein the orifice may be formed in one integral barrier member and may be varied in size by distortion of that member whereby perfect thin edged orice action may be more closely approximated. Another object is to provide an improved flow regulating valve having an adjustable throttle anda .pressure responsive compensating valve yin which the throttle comprises a single integral wall member having an opening the size of which may be varied.

Further objects and advantages of the present beunderstood, vof course, that the throttle construction is equally applicable to other uses where an adjustable thin edge orifice is desired as for example in regulating ow of fuel oil and such devices as are disclosed in the Lum Patent 2,572,761 as well as for many other purposes.

Referring now to Figure 1, there is shown a flow control valvecomprising a body I0 having a transverse' bore IZ for the reception of ya pressure responsive compensating Valve generally designated I4. The latter comprises a sleeve 4I6 retained in place by a shoulder I8 and an end plug 2B, the opposite end of the bore I2 being closed by a plug 22. The sleeve I6 has an internal bore 24 provided with a series of controllable inlet ports 26 and a series of outlet ports 28. The ports 26 communicate with a groove 30 which in turn communicates with an inlet passage 32. The ports 28 communicate with a groove 24, which in turn communicates with an inter- Y slidable in the left hand end of bore I2. A loninvention Awill be apparent frcm'xthe .following new gitudinal passage 42 connects ports 28 with opposite ends of the sleeve I6, thereby applying the pressure existing in ports 28 to the right hand 'end of valve spool 38 and to the right hand sur- A spring 43 normally urges face of piston 4I. the spool and pistonto the right with a light force.

Referring now to Figure 2,- the lower end of bore 36 opens to the left into a larger transverse bore44 and is provided Awith a rounded oval throat at 46 which is` of oval cross-section as viewed in Figure 1. Slidably mounted in bore 4 4 is an orifice member 48. The latter hasga cylindrical surface which is slidable in the bore`4 4 andprovided vwith a sealing ring 50 as well as a each other by a very small distance. The slot-58` extends vertically across the s hortdiatighterojbl the oval throat 45. Member 4S may be fo d i, any suitable hard springy material suchashard; ened steel, phosphor-bronze, beryllium copper` or any of a number of plastic materials andthe,

wall 5B is suicienty thin so that it may be readily distorted by the application of force Substantially in the direction'of the arrowsshown in Figure 2 At its left-hand end, the member 48 is closed by a plug 55 and is providedwth a plurality of radial holes 6,2. The plugvllis adapted to co-L operate with a stationary seat 64 povsit io ned in the right-hand end of boreV 44l by a screw plug BB. The latter carries a threaded adjusting rod 68,V having. a dial l@ by which the member 48 may be adjustably shifted in the borerllA.V The space @the left i Seat 64 @meets with anutlet Dassage 12 which in turn is connected with av verti-4 cal' passes@ T4 Communicating With the, right# handendfof bore l2.` Communication between passages l2 and 'i4 is by an intermediate passage 16 which extends to the back face of the body l0" and may form an outlet port for the valve as a whole.l A

In operation with the parts in the position as illustrated in Figures land 2, the valve is closed and'any uid pressure admitted at the inlet pas-y sage` 32 which may be directed through groove 3U, holes 25, passages 28, groove 34, passage 3B, and throat 45 is principaly blocked at the flexible wall 56 because the slot 58 is closed. Ifthe walls of the slit do not form a perfect seal, any leakagetherethrough will be transmitted to the interior of member 48 and through the holesat 6,2A to the interior of bore 44 where it is blocked bythe plug U being seated on seat 64. Thus the valve is closed tight and the build-up of pressure in the passages just described will be transmittedthrough passages 42 to the right-.hand face of spool 38 and piston 4l and shift thespool 38-to the leit'closing the passages 2S; Pressure in the outlet port 1B being low and acting over vthe left--` hand face of piston 4I permits such leitward movement of the spool 38.

When it is desired to open the valve and `permit a'reg-uated rate of flow therethrough, thev dial 1Q is turned toscrew the stem 68 inwardly carrying the plug iloi of the seat 64 and .bringing the-convex-wall 56 intoengagementwiththe oval sea-i546; at avprexmately the-point .shew-n by the' arrows in Figure 2, As the member 48v is moved into; engagement with the Seat further-f thefleri: ble wall 55 is distorted in a directiontending to bring the ends of the slit 58 closer to each other which resulten@ to the curved share Wall 5.6, Opening 0i the teatral Designern@ las shew-,ri in Figure. 3.; Tegernseer-'09612: in depends.; 0i @urea worries- ,amwet @if ,s movement guente the Screw Si @that the slit 58 maybe varied in area over a substantial range. With the. slit 5g open, the action is si i1- te` that vdescrilitfltbe, patent 4 ferred to in that the valve I4 takes up a position depending upon the difference in pressure between that at the inlet 32 and the back pressure at outlet 1S, so that a throttling effect occurs between lands 45 and holes 26 suflicient at al1 times to maintain a constant pressure drop across the orice represented by the slot 58,

It is well understood that the maintenance of a constant pressure drop across an orifice of a given size results in a constant rate of flow therethrough: with uid of any given viscosity. Furthermore, by reason of the fact that the wall 5 isvthirinandtheedges of the slit 58 are consequentl-y comparatively sharp or thin the flow rate will. also lreirrain substantially constant over a substantial range of viscosities.

lltwill thus be seen that the present invention provides a throttling device and ow regulating valve in which a constant ilow rate may be maintained with only negligible or' veryr smalluva. ations regardless of largevariations inthe pr sure applied to the valvel asa whole and also large variations in oil viscosity. t

Whilethe form of embodiment of theinvention ashereinndisclosed constitutes a preferred form, itk is tobe understood that'other forms might-be' ae.Qpted,.a11 om1ng which felle-W- What is claimed is as folows':

An adjustable throttle for controlling uid.

flow comprising a thin wall member forming. a barrier in a uid channel and having a configura'- tion in a curved surfaceoi revolution, andbeing. formedof a springy hard material, said wall hav ing a slit extending therethrough,` a co-operating. member of non-circular form, and means for'. varying the relative engagement of the wall mem-s ber and the non-circular member for variably deforming the wal member whereby the slit may be opened to a variable extent. v 1` 2. An adjustable throttle for` controllinguid flow in a channel'comprising a thin, metallic, convex wall member forming a barrierA in the channel and having a slft therethrough,` and shiftable means within the fluid channelifor vari-Y ably deforming the member endwise of the slit to create an adjustable orice having a` thin edge.

3. An adjustable throttle for controlling fluidv flow in a channel comprising a thin, metallic,- convex wall member'forming a barrier in the channel and having a slit therethrough, a none, circular seat member engageable with the wall member and means for shifting-one of said memf bers relative to the other to vvariably compress the wall member and variably open the slit.

ed.' in adjustabe throttle for: controlling. fluid flow a channel comprising a thin, Ymetalli@ convex wall member forming a barrer 'in the channel and having aY slit therethrough, a stationary oval seat member, and means for. .vari-I ably forcing vthe Wall-member into .engagement with the seat to variably .compress the Awall mm, berendwise of the slit whereby thefslit'xnaybe variably opened to form'V an adjustabl'thin edged finge@- Y, i L. RAYMOND TWYMAN.

REFERENCES CITED l `The followingY references are ofA recordin the f1.1@ ofi this patent: L l

UNTED STATES.- PATN'E within the scope of the claims 

